Information about even the tiniest details of our daily lives zooms along neurons in our brains and is processed and saved in some predetermined location. How and what information is stored in the memory is in part dependent on whether an individual is a man or a woman. While the underlying mechanisms that explain memory differences between men and women are largely unknown, the fact that there are differences remains an intriguing and insightful area of scientific study. New evidence, reported last week in the journal Current Directions in Psychological Science, indicates that there exist significant differences between men and women pertaining to a unique type of long-term memory known as episodic memory.

Although there are exceptions, in general, relative to men women appear to have better long-term episodic memory—memories of events or experiences, such as weddings or accidents, that tend to be verbal in nature, meaning the memories are associated with words, whether heard, spoken, or written. Another form of episodic memory is visuospatial memory, meaning the memory is associated with pictures, images, or other visual cues; however, fewer visuospatial memories appear to be stored as episodic memory.

Women have the upper hand in storing and recalling verbal episodic memories, whereas men have the upper hand in storing and recalling visuospatial episodic memories. Scientists have also discovered that women are very adept at remembering the faces of strangers and nearly anything associated with emotion, which may or may not be stored as episodic memory. Of course, what is important is not who has the best memory but how our memories work, the understanding of which may help resolve the curious observation that the ways in which men and women remember information seem to compliment one another.

Memory is a function of multiple areas of the brain, including the hippocampus and the prefrontal cortex, and can be divided into three types: sensory, short-term, and long-term. Long-term memories are basically short-term memories that have become solidified in our brains by practice and repetition. Long-term memory stores both procedural information, such as remembering how to play a musical instrument or how to drive a car, and factual information. The factual side of long-term memory is further divided into semantic memory and episodic memory. While episodic memory is specific for events and experiences, semantic memory stores information about discrete facts, such as a person’s name or the meaning of a word.

One reason why differences in memory formation exist between men and women can be attributed to hormones, primarily estrogen and androgens such as testosterone. Studies of people receiving hormone-based therapies have shed some light on the involvement of hormones in the formation and storage of memories. For example, estrogen replacement therapy in menopausal women improves long-term memory, and testosterone therapy in older men improves short-term memory.

Estrogen and testosterone have only slight differences in chemical structure. However, they have extremely wide variations in biological actions and presumably have unique affects on the growth of neurons and on the transmission of nerve impulses within the brain. In addition, neurons in different regions of the brain express diverse types of estrogen and androgen receptors on their cell surfaces. These receptors are often expressed to varying degrees. For example, a neuron may express more androgen receptors than estrogen receptors, thereby allowing testosterone to have a greater influence than estrogen on neuronal activity. Hormones also influence the flow of blood through blood vessels and thus can influence how much blood reaches different parts of the brain, which in turn could affect the growth of neurons that are critical for memory formation.

The discoveries that have been made about the storage and retrieval of information in the human brain have cast further light on the astounding complexity of memory. Adding to this complexity is the fact that the brain and memory are not static; our brains adapt and change throughout our lifetimes. This is valuable information, especially since the number of people who suffer from mental illnesses, such as depression and post-traumatic stress disorder, is on the rise. Finding ways to retain happy memories, to create new, positive memories, or to erase harmful memories can go a long way in helping these people reestablish their lives.